Pickproof lock



Dec. 13, 1949 M, SEGAL 2,491,337

PICKPROOF LOCK Filed Nov. 30, 1946Y Patented Dec. 13 1949 PICKPROOF LOCK May Segal, New York, N. Y.

Application November so,

(ci. 'zo-419) 11 Claims.

This invention `is a novel and improved pickproot cylinder lock and the objects, advantages and functional and structural features lthereof will be more particularly pointed out in the following detailed specification viewed in the light of the accompanying draw-ings wherein:

Fig. l is a longitudinal sectional view of the pickproof cylinder lock according to my invention illustrating the slidably guided accessible knob or closure elevated to permit insertion of a properly mated key into the barrel or plug to unlock the latter.

Fig. 2 is a view similar to Fig. 1 illustrating the mating key 'within the plug and the knob lowered and interlocked with the key.

Fig. V3 is a reduced front view of Fig. 1.

Fig. 3A is a view er1 the 'imesh- 3A of Fig. 3.

Fig. 4 is a view similar to Fig. 3 showing the knob or closure depressed and concentrically disposed relative to the rotatable plug.

Fig. 4A is a sectional view on the line Fig. 4.

Fig. 5 illustrates a view 'similar'to Fig. 3 but with the mating key linserted in the cylindrical plug.

Fig. 5A is a sectional view on the line SA--ll'A of Fig. 5 b ut with the plug omitted.

Fig. 6 is a 'view similar to Fig. 5 vbut with the knob depressed land the key.

Fig. 'l is a sectional view on Vthe line 1-1 of Fia 6- ig. 7^ is 'a fragmentary shown in Fig. 7, however, with omitted.

Fig. 8 is a side elevational view of a mating key.

Fig. 9 is a perspective view ofthe cylinder lock.

Fig. 10 is a view taken on the line IIL-IU of Fig. 1 to illustrate stop means for the slidable knob.

Fig. 11 is a fragmentary view of Fig. 2 however showing a slightly modiedmating key removably concealed and interlocked by the slidably guided knob, and

Fig. l2 is a sectional view Fig. 11.

Illustrative of the embodiment disclosed, the cylinder lock is generally designated CL Yand is characterized by a housing or casing C having -a longitudinally disposed cylindrical Ybore I0 for rotatably guiding the cylindrical plug or barrel P. Thehousing C is provided with spaced vertical and cylindrical bores II for slidably guiding the cylindrical VVdriving pins l2 normally urged v-'iew of the plug on the line I2--fl 2 of removably interlocked with the slidable knob 1946, `Serial No. '713,238

downwardly by the helicoidal springs I3 appropriately retained within the casing C.

Cylindrical tubular pins I4 are slidably guided in the cylindrical bores as I5 in the rotatable plug P and normally project into the key receiv ing longitudinally arranged slot I6 (Fig. 1). The tumbler pins I4 vare of an unequal height and are adapted as is well understood to be actuated by properly cut shank S of 'a mated paracentri'c key K.

With the key K removed from plug, the driver pins I2 are in part disposed within the bores I5 and consequently the plug is re'- tained against rotation.

Where the key is fully inserted into the plug the tumbler and driver pins properly line up (Fig. 2) to permit rotation l'of the plug relative to the cylinder.

Associated with front thereof is the the plug and accessible at the slidably 'guided latching member or knob LM which is provided with a circular head H of a Vsize coe'xt'ensi've with the size of the circular front face I8y of the plug which embodies 'a dovetailed reentra-ntand diametrically disposed recess `broadly denotedIS (Figs. '7, '7A and 9) havling the rear vertical face meeting with the forwardly extending inclined and converging and retaining faces 2| of the retaining lips or guide means 22.

Slidably guided by the inclined faces 2l is the forwardly extending 'dovetail shaped diametrically disposed lboss '23 of the Vknob LMhaving the div'erging lips or tracks 24 interlocked with and slidablycooperating with the retaining lips or vtracks 22 of the plug P and with 'the spaced lips or tracks 25 defining with 'the rear face 26 in the front or anterior part ofthe casing C a vertically disposed reentrant and dovetailed recess 26' (Fig. 5A), the guide lips 25 defining the forwardly projecting and converging 'retaining faces 29 of the track means A25.

lKnob LM is interrupted by a slot or recess 2 1 adapted to removably receive andhouse at least the proximal or front part 28 of the shank S of the key. This knob is also provided with the forwardly projecting boss 30 having the diametrically arranged slot 3l defined in part by the forwardly projecting wings or lugs 34 adapted to removably straddle and interlock with the rear part 32 of the bowB o f the key K, part 32 of the bow B (Fig. 2) removably fitting intoslot or gap- 3'I of the knob when the latter has been shifted downwardly and if shifted completely down, lips 2 4 are completely withinthe limits of the plug 3 and free of the spaced track means or lips 25 of the casing, the slots 21 and 3i at all times being oppositely disposed in respect to common web 33 of the knob as illustrated.

The plug P is automatically unlocked from the casing C when the lips or projecting means 24 of the knob LM strike the lower curved part 35 adjacent the bore 36 of the casing C and this bore forms the bearing for the enlarged cylindrical head 31 of the rotatable plug. Part 35 may thus be considered as stopV means for the slidably guided knob or closure LM (Figs. 2 and 4). In Fig. 4 the knob LM is unlocked from the casing and against the stop portion 35 of the bore 36, that is, the knob serves as a closure to render keyway IB inaccessible. By applying a finger thrust on the knob LM the latter may be slidably raised from the position indicated in Fig. 4 to its highest elevation shown in Fig. 3 at which time the knob still locks the plug against rotation.

Of importance is the coaction of the lips 24 of the knob with the curved portions or elbows 31 of the crown or upper portion 38 of the recess 26'. These curved portions 3'! form a contracted part of recess 26 drawal of these lips 24 from the rotatable plug P when the latter is fully raised. Hence in the fully raised position of the knob, they latter is therefore still interlocked with the plug (note Fig. 1) wherein lips 22 of the plug are still interlocked with lips 24 of the knob, nevertheless keyway I6 is rendered fully accessible to allow for insertion of the key (Figs. l, 3 and 9). Consequently even if a picking tool (not shown) be inserted in the keyway to actuate the tumbler pins I4 from the position shown in Fig. 1 to that illustrated in Fig. 2, the plug P still could not be turned for effectively revolving the conventional tail piece T carried by the plug because the knob LM at all times i-s interlocked with the plug and the only time that the plug may be turned or rotated is when the key is fully inserted into the keyway I6 (Figs. 2 and l0) and the latching member or knob LM is shifted completely downwardly for fully interlocking with the key.

For automatically holding the knob in a lowered or rai-sed position, spheroidal antifriction means 4D backed up by a helicoidal spring 4I is confined in a socket or bore 42, the ball or antifriction means being constantly urged against the rectilinear Walls or faces 28 and 26 of the alined recesses I9 and 26' of the plug P and cylinder C respectively, when the knob is shifted to open or close the keyway I6. By this arrangement the knob may be held automatically even in a partly raised or lowered position.

Following the insertion of the key in the plug (Fig. 5), the knob LM is shifted downwardly against the resistance of the braking means dened by the ball 4I) and spring 4I to the position shown in Fig. 6, thus unlocking the knob from the casing C. On downward displacement of the knob, portion 28 of the key is straddled by the spaced walls of the recess or slot 21 and portion 32 of the bow B is straddled by that is, the key is now removably interlocked locked from the casing and at a time when the tumbler and driver pins I2 and I4 are lined up as illustrated in Fig. 2. N ow by rotating the key the plug may be desirably revolved to appropriately rotate the tail piece T as required. Following such operation, the knob may again be slid- -ably raised to be free of the key, permitting withdrawal of the key removal from the plug., Purto preclude complete withspaced lugs 34,

suant to such removal the knob is lowered close to the keyway I 6.

In Fig l1, the key K has no bow as B of the type shown in Figs. 2 and 8. Instead the front portion 23 thereof is provided with nger receiving grooves 29'. When the knob is fully raised, the walls of recess 2T completely clear the key K permitting the removal thereof from the plug. With the knob fully raised the key may be also fully inserted into the keyway, and thereafter the knob is fully lowered whereby the front portion 28 is disposed within recess 21 and removably interlocked with the walls thereof. In other aspects the form illustrated in Fig. 11 is along the lines shown in Figs. 1-10.

In all of the embodiments disclosed with the key inserted into the key receiving slot or keyway I6 and with the latching means or knob LM fully depressed and interlocked with the key, the plug of course may be rotated relative to the casing to actuate or revolve the tail piece T. This may be accomplished by grasping and vrotating the spaced wings or lugs 34 which constitute manipulatable means.

The key can only be removed from the plug upon shifting the latching means or knob LM to its uppermost position in which instance the key is unlocked from the latching means and can readily now be withdrawn from the plug but even at such times as previously pointed out the latching means is still interlocked with the plug and even though the tumblers I4 thereof may be tainpered with the cylinder is pickproof as it cannot be revolved except by the use of its mating or duplicate key.

Various changes may be made in details of construction and arrangement of parts without departing from the spirit of the invention or sacrificing any of the advantages thereof inherent therein.

I claim:

l. A cylinder lock adapted to be unlocked by a key, comprising; a casing having an anterior portion embodying track means, a plug provided with a slot for receiving said key and rotatablydisposed within said casing and having guide means, latching means accessible at the front part of said plug and casing and having rearwardly disposed projecting means slidably guided by and interlocking with said track means and guide means to preclude rotation of said plug relative to said casing, and means to limit displacement of said latching means in a direction away from said plug to render said slot accessible for insertion of said key thereinvat which time said projecting means is still interlocked with said guide means and track means. f

2. A cylinder lock adapted to be unlocked by a key, comprising; a casing having an anterior portion embodying spaced track means, a plug provided with a slot for receiving said key and rotatably disposed within said casing and having spaced guide means, latching means accessible at the front partvof said plug and casing and having rearwardly disposed and spaced projecting means slidably guided by and interlocking with said track means and guide means to preclude rotation of saidplug relative to said casing, and means to limit displacement of said latching means in a direction away from said plug to render said slot accessible for insertion of said key therein at which time said projecting means are still interlocked with said guide means and track means. I

3. Acylinder lock adapted to be unlocked by a key, comprisigj a casing' l'iavi'rigan anterior portion embodying a reentrant recess boundedby spaced track sans, a plus provided with a siot for receiving said key and ro `ly disposed within said casing' and Yhaving a reeiitr'ant recess bounded by spaced guide means, latchingmeans accessible at the front part f 'said plug and casvr""aded ing4 and having Vrearwardly dispos Vd projecting lips slidably guided by and inery cking with said track means and vguide to preclude rotation of said plug relative to said casing, and means to limit displacement of said latching means in a direction away from said plug to render said slot accessible for insertion of said key therein at which time said projecting means are still interlocked with said guide means and track means.

4. A cylinder lock adapted to be unlocked by a key, comprising; a casing having anterior portion embodying track means, a plug provided with a slot for receiving said key and rotatably disposed within said casing and having guide means, latching means accessible at the front part of said plug and casing and having rearwardly disposed projecting means slidably guided by and interlocking with said track means and said guide means to preclude rotation of said plug relative to said casing, means 'to limit displacement of said latching means in a direction away from said plug to render said slot accessible for insertion of said key therein at which time said projecting means is still interlocked with said guide means and track means, and spring controlled braking means to resist displacement o said latching means relative to said plug.

5. A cylinder lock adapted to be unlocked by a key, comprising; a casing having an anterior portion embodying track means, a plug provided with a slot for receiving said key and rotatably disposed within said casing and having guide means, latching means accessible at the front part of said plug and casing and having rearwardly disposed projecting means slidably guided by and interlocking with said track means and guide means to preclude rotation of said plug relative to said casing, and means to limit displacement of said latching means in a direction towards said plug to render said slot inaccessible at which time said projecting means is unlocked from said track means but interlocked with said guide means to permit rotation of said plug relative to said casing ifl said key be disposed in said slot.

6. A cylinder lock adapted to be unlocked by a key, comprising; a casing having an anterior portion embodying spaced track means, a plug provided with a slot for receiving said key and rotatably disposed within said casing and having spaced guide means, latching means accessible at the front part of said plug and casing and having rearwardly disposed and spaced projecting means slidably guided by and interlocking with said track means and guide means to preclude rotation of said plug relative to said casing, and means to limit displacement or' said latching means in a direction towards said plug to render said slot inaccessible at which time said projecting means are u locked from said truck means but interlocked with said guide means to permit rotation of said plug relative to said casing if said key be disposed in said slot.

7. A cylinder lock adapted to be unlocked by a key, comprising; a casing having an anterior portion embodying track means, a plug provided with a slot for receiving said key and rotatably dis.-

pas

mg means faccessib e at the fro't part of f interlocking with said track means and guidemeans to preclude rotation of said plug relative tc said` casing,y means to limit displacement ofA said latching means in a direction towards said? plug to render said slot inaccessible at which time said vprojecting means is unlocked from said track means but interlockedv with said guide means to permit rotation of said plug relative to said casing if said key be disposed in said slot, and spring controlled braking means to resist displacement of said latching means relative to said plug or casing.

8. A cylinder lock adapted to be unlocked by a key, comprising; a casing having an anterior por tion embodying track means, a plug provided with a slot for receiving said key and rotatably disposed within said casing and having guide'A means, latching means accessible at the front part of said plug and casing and having a rearwardly disposed hollow boss for removably interlocking with said key upon displacement of said latching means towards said plug and provided'- with spaced lips slidably guided by and interlocking with said track means and guide means to preclude rotation of said plug relative to said casing, means to limit displacement of said latching means in a direction towards said plug to render said slot inaccessible at which time said lips are unlocked from said track means but interlocked with said guide means to permit rotation of said plug relative to said casing if said key be disposed in said slot, and manipulatable means carried by said latching means.

9. A cylinder lock adapted to be unlocked by a key having a shank and a bow, comprising; a casing having an anterior portion embodying track means, a plug provided with a slot for receivihg said key and rotatably disposed within said casing and having guide means, latching means accessible at the front part of said plug and casing and having a rearwardly disposed hollow boss for removably interlocking with said shank and provided with spaced lips slidably guided by and interlocking with said track means and guide means to preclude rotation of said plug relative to said casing, spaced wings carried by said latching member for removably interlocking with said bow, and means to limit displacement of said latching means in a direction towards said plug to render said slot inaccessible at which time said lips are unlocked from said track means but interlocked with said guide means to permit rotation of said plug relative to said casing if said key be disposed in said slot.

10. A cylinder lock adapted to be unlocked bya key, comprising; a casing having track means, a plug provided with a slot for receiving said key and rotatably disposed within said casing and having guide means, latching means having projecting means slidably guided by and interlocking with said track means and guide means to preclude rotation of said plug relative to said casing, and means to limit displacement of said latch means in a direction away from said plug to render said slot accessible for insertion of said key therein at which time said projecting means is still interlocked with said guide means and track means.

11. A cylinder lock adapted to be unlocked by a key. comprising; a casing having track means,

ltitressind'essere` a'y a ravine een@ means,-

a plug provided with a slot for receiving said key and rotatably disposed within said casing and having guide means, shiftable Alatclfiing means having rearwardly disposed projecting means slidably guided by and interlocking with said track means and guide means to preclude :rotation of said plug relative to said casing, and means to limit displacement of said latch means in a direction away from said plug to render said slot accessible for insertion of said I key therein at which time said projecting means is still interlocked with track means.

said guide means and MAY SEGAL.

REFERENCES' CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number 

